Constant-current generator.



No. 855,485. PATENTED JUNE 4, 1907 C. P. STEINMETZ.

CONSTANT CURRENT GENERATOR.

APPLICATION FILED AUG. 7. 1905.

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G. P. STBINMETZ. CONSTANT CURRENT GENERATOR.

APPLICATION IILED AUG. 7, 1905.

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CHARLES P. STEINMETZ, OF SOHlL NEOT ADY, NEVV YORK, ASSIGNOR TO GENERALv ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

' Specification of Letters Patent.

Patented June 4, 1907.

' Applicationfiled August 7,1905. Serial K0. 272,982.

To all whom it may concern.-

Be it known that 1, CHARLES P. STEIN- Mnrz, a'citizen of the United States, residing at Schenectady, county of Schenectady,

State of New York, have invented certain new and useful Improvements in-Constant- Current Generators, of which the following is a specification.

My invention relates to dynamo-electric machines for supplying constant direct-current, and its object is .to render it possible to build generators of this type of higher ca acity than has heretofore been feasible. onstant-current generators have been chiefly employed heretofore in sup lying series arelight circuits. When ap fied to this and similar uses, the amount 0 current is limited by the re uirements of the circuit that is supplied, an the voltage is limited by the diffi culty of obtaining successful commutation with voltages above certain values. Consequently, the capacity of such generators has been limited. heretofore, and it has been customary to equip a central station designed for supplying series arc-light circuits with a large number of small machines. Such a station has a higher first cost, reater maintenance expenses, and lower efficiency, than would be obtainable provided a few large machines could be used in'place of the numerous small generators.

My invention in its broadest aspect consists in inserting series transformers between the armature winding and the rectifying commutator. By employing a plurality of setsof transformers and a plurality of sets of connnu tatorsi, the outputof the armature may be dividedamong the connnutators so that the load on each commutator need be no. greater than can be readily commutated, the capacity of the machine may be made anything that is desired, and the induced voltage and armature current may bear any desired relation to each other, while at the same time by properly proportioning the transformers each commutator receives a current of the amount required in the circuit supplied therefrom, and of a voltage of an a mount which can be successfully commutated.

My invention then consists in a constantcurrent generator having a plurality of armature windings of the open-coil type, and a plurality of sets of series transformers, each armature winding being connected in closed circuit through the primaries of one transformer of each set, the secondaries of the transformers of each set being connected to one of a plurality of rectifying commutators. My invention will best be understood by reference to the accompanying drawings, in which Figure 1 shows a side elevation in crosssection of a constant-current generator constructed in accordance with my invention; Fig. 2 shows an end elevation. of the transformers and the support therefor; and Fig. 3 shows a development on a plane surface of a suitable form of field armature winding.

In Fig. 1, F represents the field winding, and A the armature winding. These windings may be of any well-known type, but I have illustrated and prefer touse a distributed winding on each member of a type disclosed in a companion application, Serial No. 272,949, filed August '7, 1905. As described in that application, by using distributed windingsa arge armature reaction may be obtained, and by placing the brushes as shown in Fig. 3, so that the lines of magnetization of the field and armature make a small angle with each other, the armature reaction tends to cause the machine to deliver constant current; which tendency may be increased by designing a machine so as to be saturated at normal load. While I have illustrated in Fig. 3 a machine thus arranged, it will be understood that my invention is not limited to this design of machine, but is equally applicable to agenerator constructed in any well-known way, so as to produce constant-current. D represents a laminated ring carried on the armature shaft and supported between suitable spiders E. T T represent transformer windings interlinked with the laminated ring D, which forms the magnetic circuit for each of the several transformers.

formers. The connections of the windings are shown in Fig. 3. F represents the field winding, which is shown as a distributed winding, but which may be of any other type if referred, and which is connected to a suit- C C represent two commutators mounted on the armature shaft and connected to the secondaries of the several trans-- stead of being connected to thesegments of the rectifying commutator in the usual manner, is connected in a closed circuit through the primaries of one transformer of each of 5 two sets, which are indicated respectively by T and T The secondaries of the transformers T are connected to the segments of a commutator C, and the secondaries of the transformers T are similarly connected to th segments of a commutator C. These coi fmutators are supplied with sets of br shes B and B each arranged in the usual manner and each supplying an independent circuit, indicated by L and L I have indicated diagrammatically a regulating rheostat comprising a resistance R included in the field circuit, a rheostat arm 1" and a controlling magnet comprising two solenoids S and S connected in the two work-circuits respectively, and opposed by a tensionspring 8. It will be understood that this regulator is purely diagrammatic and that any well-known typemay be employed.

Itiis evident that if the transformers T and 'I are similarly proportioned, the same current will be maintained in both workcircuits, while the relative voltage impressed upon the two circuits may be anything that is desired. On the other hand, if constant currents of different values are desired in the two circuits, this result may be obtained by properly proportioning the two sets of series transformers.

Although only two sets of transformers and two eommutators are shown, it is obvious that the arrangement may be multiplied indefinitely, so that any number of circuits may be supplied with constant current of any desired amount and of any desired voltage. Y

I do not desire to limit myself-to the particular construction and arrangement of parts here shown, but aim in the a pended claims -to cover all modifications wliich are within 45 the scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. Ina constanturrent generator, 'a plurality of armature v. indin s of the open-coil type, a plurality of sets 0' series transfonners, each of the armature windings being connected in closed circuit through the primaries of one transformer of each set, and a plurality of rectifying commutators connected respectively to the secondaries of the several sets of transformers. 2. In a constant-current generator, a plurality of armature windings of the open-coil type, a plurality of sets of series transformers revolving with the armature, each of the armature coils being connected in closed circuit through the primaries of one transformer of each set, and a plurality of rectifying commutators revolving with the armature and connected respectively to the secondaries of the several sets of transformers.

3. In a constant-current generator, a plurality of armature windings of the open-c0il type, a laminated body carried by the armature, a plurality of transformer coils carried by said body, each armature winding being connected in closed circuit through a plurality of transformer primaries in series, and a plurality of rectifying commutators connected to the secondaries of said transformers.

4-. In a constant-current generator, a plurality of armature windings of the open-coil type, a laminated ring carried by the ar1nature, a plurality of transformer windings interlinked with said ring, each armature being connected in closed circuit through a plurality of transformer primaries in series, and a plurality of rectifying commutators connected to the secondaries of said transformers.

In witness whereof, I have hereunto set my hand this 4th day of August, 1905.

CHARLES P. STEINMETZ.

Witnesses:

BENJAMIN B. HULL, MABEL E. HULL. 

